Astron. Astrophys. 338, 511-520 (1998)

Seismology of Scuti stars in the Praesepe cluster

II. Identification of radial modes and their associated stellar parameters

small.htm M.M. , Hernández ^{* 1}, F. , Pérez Hernández ¹, E. , Michel ², J.A. , Belmonte ¹, M.J. , Goupil ², Y. and Lebreton <sup>2

1</sup> Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife, Spain
² DASGAL, URA CNRS 335, Observatoire de Paris, F-92195 Meudon, France

Received 5 January 1998 / Accepted 20 July 1998

Abstract

An analysis based on a comparison between observations and stellar models has been carried out to identify radial modes of oscillations in several multi-periodic  Scuti stars of the Praesepe cluster (BU, BN, BW and BS Cnc). The assumption that all the stars considered have common parameters, such as metallicity, distance or age, is imposed as a constraint. Even so, there is a large number of possible solutions, partially caused by the rotational effects on the pulsation frequencies and on the stars' positions in the HR diagram, which need to be parameterized. When pairs of radial modes are assumed to be present in every star, only a few similar identifications are found to be possible, corresponding to a metallicity of and an amount of overshooting of . They are associated with a distance modulus of 6.43 and an age of 650 Myr. Estimates of mass and rotation rates for each star are also deduced.

Key words: stars: oscillations ffi Scu open clusters and associations: individual: Praesepe

* Also Associated Researcher at DASGAL

Send offprint requests to: M.M. Hernández, (mmanuel@iac.es)

© European Southern Observatory (ESO) 1998

Online publication: September 14, 1998

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